Problems with diseased and arthritic hip joints have been with the human race for many years. Since early in the present century, various proposals and operative techniques have been proposed for partial or complete replacement of the hip joint. One prior arrangement which has met with considerable success is disclosed in U.S. Pat. No. 4,123,806, granted Nov. 7, 1978, to Dr. Harlan C. Amstutz, et al., with Dr. Amstutz being one of the co-inventors in the present case. Other prior proposals are shown in U.S. Pat. Nos. 4,173,797, granted Nov. 13, 1979; 3,894,297, granted July 15, 1975; 4,164,794, granted Aug. 21, 1979; and British Patent No. 2,117,646, published Oct. 19, 1983.
With regard to the hip socket, or acetabular components, some problem has been encountered, particularly with more active patients, in the loosening of the component. More particularly with the frequent stressing of the hip joint as a person walks, if the joint is not fairly rigid and securely fastened into the hip joint, the resultant micromovements will become cumulative, and the loosening of the hip joint prosthesis will result. Another problem has been the limited amount of bone which may be available near the hip socket. Thus, with some proposed prosthesis, such as that shown in U.S. Pat. No. 3,894,297, the prosthesis is so large, that there may be insufficient surrounding bone structure, in some cases to properly retain and support the fixture. In other cases, there have been materials failures, and the cements which have been used in some cases have failed, in the case of some active patients. In addition, the problem of accurately fitting the prosthesis securely and tightly in place is a serious problem, particularly under the conditions encountered during the course of a major operation.
Accordingly, a principal object of the present invention is to provide an acetabular artificial hip joint component which uses minimum space and which will be firmly and permanently secured in position through biological ingrowth.